opentofu/terraform/util.go
Matt Good 21b0a03d70 Support for multiple providers of the same type
Adds an "alias" field to the provider which allows creating multiple instances
of a provider under different names. This provides support for configurations
such as multiple AWS providers for different regions. In each resource, the
provider can be set with the "provider" field.

(thanks to Cisco Cloud for their support)
2015-04-20 14:14:34 -07:00

73 lines
1.4 KiB
Go

package terraform
import (
"strings"
)
// Semaphore is a wrapper around a channel to provide
// utility methods to clarify that we are treating the
// channel as a semaphore
type Semaphore chan struct{}
// NewSemaphore creates a semaphore that allows up
// to a given limit of simultaneous acquisitions
func NewSemaphore(n int) Semaphore {
if n == 0 {
panic("semaphore with limit 0")
}
ch := make(chan struct{}, n)
return Semaphore(ch)
}
// Acquire is used to acquire an available slot.
// Blocks until available.
func (s Semaphore) Acquire() {
s <- struct{}{}
}
// TryAcquire is used to do a non-blocking acquire.
// Returns a bool indicating success
func (s Semaphore) TryAcquire() bool {
select {
case s <- struct{}{}:
return true
default:
return false
}
}
// Release is used to return a slot. Acquire must
// be called as a pre-condition.
func (s Semaphore) Release() {
select {
case <-s:
default:
panic("release without an acquire")
}
}
// resourceProvider returns the provider name for the given type.
func resourceProvider(t, alias string) string {
if alias != "" {
return alias
}
idx := strings.IndexRune(t, '_')
if idx == -1 {
return ""
}
return t[:idx]
}
// strSliceContains checks if a given string is contained in a slice
// When anybody asks why Go needs generics, here you go.
func strSliceContains(haystack []string, needle string) bool {
for _, s := range haystack {
if s == needle {
return true
}
}
return false
}